It is a long lasting desire in the manufacture of articles, and especially of disposable absorbent articles, such as diapers, or at least pre-cursors thereof, to produce various sizes on one and the same manufacturing equipment without tedious, costly, and time consuming change of size specific parts of the equipment.
In JP2004-248825 (Zuiko—Takao) the processing of a sheet in the manufacturing of apparel such as underpant/trouser and diaper is described. The apparels of different sizes are processed in the same apparatus, only by changing the introduction position of the sheets of a constant length.
In US2003/0047273 (Zuiko—Kojo) a semi finished product is manufactured by changing circumferential velocity of the rotating unit, according to the size of semi finished product for each process cycle.
U.S. Pat. No. 3,828,367 (ELASTELLE FONTANILLE—cited in US'273) shows the manufacturing of products such as disposable briefs wherein a flexible non-elastic element on which is fixed locally at least one stretched elastic element adapted to confer on the the non-elastic element the faculty of stretching, the elastic element being fixed in position in the stretched condition. The method comprising essentially the steps of: causing a continuous strip of the non-elastic element to travel, without being subjected to deformation, at a constant speed and always in the same direction; simultaneously causing at least one continuous tape or band of the elastic element to move in the same direction and at the same speed as the strip.
The combining of various webs is a well known operation, such as described in U.S. Pat. No. 6,059,710 (K-C/Rajala), wherein a primary component is cut from a web and is transferred to overlay on a secondary web. The secondary component is then cut on the die to a longer extension, with its longitudinal center coinciding with that of primary component. The combined primary and secondary component are transferred to an embossing roll and engraved with identical shapes. All the die rolls run at different speeds and the center of the components are coincided by adjusting the rotational phase angle of any one of the cutting die rolls.
EP974323A1 (Schmitz) shows a transporting apparatus for manipulating a continuous web which has support surfaces lying in an arc around the circumference of a circular path, which with web loop forming means give variable velocity difference between the adjacent web supports, are rotated about the axis of the circular path, such that distances between adjacent supporting surfaces vary upon rotation. EP1004285A1 (Schmitz) discloses a web handling process, wherein a web portion moves quicker when a portion is cut into separate lengths, than when it is cut off the web. The web portions are applied to a receiving web, which is then cut.
In WO2006103487A1 (Schmitz, C4S) the described method involves a moving web material from a web supply unit towards a process end section along an overall web path. A web path splitting unit positioned along the overall web path is provided. The web path is divided on the web path splitting unit into web sub-paths. The web material is transferred out of initial contact regions of a web support unit into an operating region of the web support unit. The web material is transferred out of the initial contact regions of web support unit into the operating region, thus precisely handling the web material in an efficient manner.
However, in none of the cited documents there is taught a way how to allow manufacturing articles of varying sizes over a very wide size range essentially uninterruptedly (“on the fly”) at high speeds, nor how to design a respective equipment. Also, nowhere is taught how to make both a closed pant structure in the same machine as an open type diaper without changing significant parts of the manufacturing line.